Effects of Different Processing Methods of Coffee Arabica on Colour, Acrylamide, Caffeine, Chlorogenic Acid, and Polyphenol Content.

An effect of a processing method (dry and wet) and a degree of roasting (light, medium, and dark) of 15 coffee (Coffea arabica) samples on the content of caffeine, chlorogenic acid (CQA), total polyphenols (TPP), acrylamide (AA), and on the colour parameters L*, a*, and b* was evaluated. Neither processing nor roasting affected caffeine content (p > 0.05). The degree of roasting accounted for 46% and 72% of explained variability of the CQA content and AA content, respectively (p < 0.05). AA content was in the range from 250 (wet-processed, light-roasted samples) to 305 µg·kg-1 (wet-processed, dark-roasted coffees), but the dark roasting only tended (p > 0.05) to increase AA content. Wet-processed, dry-roasted coffee had higher (p < 0.05) TPP content (48.5 mg·g-1) than its dry-processed, dry-roasted counterpart (42.5 mg·g-1); the method of processing accounted for 70% of explained variability of TPP. Both the method of processing and the degree of roasting affected the L*, a*, and b* values (p < 0.01), but the lower values (p < 0.05) of these parameters in the dark-roasted samples were found only within the wet processing. A negative correlation between the AA content and lightness (L*) was established (r = -0.39, p < 0.05). It was concluded that from the consumers' viewpoint, the results of the present study indicate relatively small differences in quality parameters of coffee irrespective of the method of processing or degree of roasting.

Fatty acid composition, oxidative stability, and sensory evaluation of the sausages produced from the meat of pigs fed a diet enriched with 8% of fish oil.

The objective of the present study was to increase by dietary means the long-chain polyunsaturated fatty acid (LC-PUFA) n-3 content in selected meat products. Fatty acid (FA) composition, texture, sensory characteristics, and oxidative stability were determined in the Vienna sausages (V-sausages) and Bologna-type salami (B-salami) produced from the meat of six pigs fed a standard feed (control, C) and six pigs fed a standard feed enriched with 8% of fish oil (F), respectively. The saturated FA content in the unheated FV and FB products was decreased (p < 0.05) by 24% and 39%, PUFA n-6/n-3 ratio improved (p < 0.001) from 13.9 to 2.8 and from 13.5 to 2.6, respectively. LC-PUFA n-3 content in the VF and BF products was 360 and 214 mg/100 g, which corresponds to 80% and 48% of the recommended daily intake. Interestingly, dietary fish oil decreased (p < 0.01) instrumentally the measured core hardness of the V-sausages, but increased (p < 0.001) this texture characteristic in the B-salami. Malondialdehyde content in the VF and BF products increased (p < 0.05) on average by 23% and the flavor of the heated FV sausages scored lower (p < 0.05) in comparison with the C-counterparts.

Effect of High Dietary Level (8%) of Fish Oil on Long-Chain Polyunsaturated Fatty Acid n-3 Content in Pig Tissues and Plasma Biochemical Parameters.

There were two objectives of the present study using dietary fish oil (FO) in pigs: to use pigs as a model for studying the effects of high FO doses on selected physiological markers; and to evaluate the physical traits and nutritive value of pork enriched with long-chain polyunsaturated fatty acids n-3. Two groups of six female pigs were fed for 30 days with either a standard feed mixture (control, C) or the same mixture supplemented with 8% FO (F). Physical characteristics of the muscle, fatty acid deposition in tissues and selected hematologic and plasma markers were tested. The daily weight gain of the F-pigs was lower in comparison with controls (p < 0.05). Dietary fish oil decreased Warner-Bratzler shear force of the longissimus muscle (p < 0.01). The eicosapentaenoic and docosahexaenoic acid content was higher (p < 0.05) in all tested F-tissues. Dietary fish oil had no effect on plasma cholesterol (p < 0.05), but it increased plasma triacylglycerol levels by 260% (p < 0.05), and increased counts of leukocytes, neutrophils, and eosinophils in the blood plasma (p < 0.05). In conclusion, high dietary FO improved the texture and nutritive value of meat, but negatively affected plasma biochemical parameters.

Effect of Different Method of Drying of Five Varieties Grapes (Vitis vinifera, L.) on the Bunch Stem on Physicochemical, Microbiological, and Sensory Quality.

The influence of the drying technique on certain quality attributes of dried grapes was analysed. Five varieties of grape were used in this study (Bezsemenné, Perlette, Vrboska, Beauty seedless, and Jakubské). All the varieties were dried using four methods: drying at 40 °C, combined drying (70, 65, and 60 °C), drying at 70 °C, and lyophilisation. The quality attributes such as total soluble solids, water activity, content of vitamin C, the colour parameters (L*, a*, b*), and microbiological (colony forming units, moulds, yeasts) and sensory (smoothness, gloss, colour, odour, chewability, juiciness, flavour, and overall impression) analysis were determined, depending on the method of drying. Lyophilised grapes from the Jakubské variety had the highest vitamin C content. They contained 0.58 mg of vitamin C per 100 g of dried grapes. However, no significant differences between varieties in vitamin C content were found. This confirmed concerns about the negative impact on the nutritional quality of dried grapes with increasing temperature. The lowest total count of microorganisms (CFU), moulds, and yeasts were determined after using highest drying temperature (70 °C). Higher CFU values were determined in lyophilised grapes, and then followed by grapes dried at 40 °C. Lyophilised grapes and grapes dried at 40 °C achieved the best sensory rating in general. The final product was intended to have a unique appearance while maintaining the evaluated quality parameters.